WIDE-FIELD IMAGING USING NITROGEN VACANCIES

• US 20150001422A1
• Filed: 06/27/2014
• Published: 01/01/2015
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Englund, Dirk Robert, Trusheim, Matthew Edwin
• Granted Patent: US 9,766,181 B2
• Time in Patent Office: Days
• US Class Current: 250/459.1
• CPC Class Codes: G01N 2021/6421 Measuring at two or more wavelengths
• CPC Class Codes: G01N 21/6458 Fluorescence microscopy fluorescence microscopes per se G02B21/0076 and G02B21/16
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 21/6489 Photoluminescence of semiconductors

Abstract

Nitrogen vacancies in bulk diamonds and nanodiamonds can be used to sense temperature, pressure, electromagnetic fields, and pH. Unfortunately, conventional sensing techniques use gated detection and confocal imaging, limiting the measurement sensitivity and precluding wide-field imaging. Conversely, the present sensing techniques do not require gated detection or confocal imaging and can therefore be used to image temperature, pressure, electromagnetic fields, and pH over wide fields of view. In some cases, wide-field imaging supports spatial localization of the NVs to precisions at or below the diffraction limit. Moreover, the measurement range can extend over extremely wide dynamic range at very high sensitivity.

Claims

1. A method of imaging at least one of an electric field, magnetic field, temperature, pressure, or strain applied to a color center, the method comprising:

(A) applying a magnetic field from a microwave source to the color center so as to manipulate an electron spin state of the color center;

(B) irradiating the color center with an optical pulse from a light source so as to excite the color center from a first energy level to a second energy level and to induce emission of fluorescence from the color center, the fluorescence representative of the at least one of the electric field, magnetic field, temperature, pressure, or strain applied to the color center; and

(C) imaging, with a wide-field imaging system, the fluorescence emitted by the color center onto a detector array.

2. The method of claim 1, further comprising, before (A):

disposing the color center on a surface of an inorganic material; and

exposing the inorganic material to the at least one of the electric field, magnetic field, temperature, pressure, or strain.

3. The method of claim 1, wherein the color center is disposed within a nanodiamond, and further comprising, before (A):

functionalizing a surface of the nanodiamond; and

disposing the nanodiamond within organic tissue.

4. The method of claim 1, wherein (A) comprises applying a plurality of microwave pulses to the plurality of color centers in an absence of any other magnetic field.

5. The method of claim 1, wherein:

the color center has a first orientation with respect to the magnetic field, and

(A) further comprises manipulating an electron spin state of another color center in the, the other color center having a second orientation different than the first orientation with respect to the magnetic field.

6. The method of claim 1, wherein (C) comprises irradiating the color center with another optical pulse from the light source within a relaxation time associated with the second energy level.

7. The method of claim 1, wherein (C) comprises imaging fluorescence emitted by a plurality of color centers onto the detector array with the wide-field imaging system.

8. A system for imaging at least one of an electric field, magnetic field, temperature, pressure, or strain applied to a color center, the system comprising:

a light source, in optical communication with the color center, to irradiate the color center with an optical pulse so as to excite the color center from a first energy level to a second energy level and to induce emission of fluorescence from the color center, the fluorescence representative of the at least one of the electric field, magnetic field, temperature, pressure, or strain applied to the color center;

a microwave source, in electromagnetic communication with the color center, to apply a magnetic field to the color center so as to manipulate an electron spin state of the color center; and

a wide-field imaging system, in optical communication with the color center, to image the fluorescence emitted by the color center onto a detector array.

9. The system of claim 8, wherein the color center comprises a nitrogen vacancy.

10. The system of claim 8, wherein the color center is disposed on a surface of an inorganic material exposed to the at least one of the electric field, magnetic field, temperature, pressure, or strain applied to the color center.

11. The system of claim 8, wherein the color center is disposed within organic tissue exposed to the at least one of the electric field, magnetic field, temperature, pressure, or strain applied to the color center.

12. The system of claim 8, wherein the light source is configured to emit the optical pulse at a wavelength of about 532 nm.

13. The system of claim 8, wherein the microwave source is configured to apply a plurality of microwave pulses to the color center in an absence of any other magnetic field.

14. The system of claim 8, wherein the microwave source is configured to apply the magnetic field at a first orientation with respect to the color center and at a second orientation with respect to another color center so as to manipulate the electron spin state of the color center and the electron spin state of the other color center.

15. The system of claim 8, wherein the light source is configured to irradiate the plurality of color centers with another optical pulse within a relaxation time associated with the second energy level.

16. The system of claim 8, wherein the wide-field imaging system is configured to image fluorescence emitted by a plurality of color centers onto the detector array.

17. A system for imaging at least one of an electric field, magnetic field, temperature, pressure, or strain applied to the color center applied to a nanodiamond, the system comprising:

a laser, in optical communication with the nanodiamond, to illuminate the nanodiamond with an optical pulse so as to simultaneously to induce emission of fluorescence from a nitrogen vacancy in the nanodiamond and to excite the nitrogen vacancy in the nanodiamond from a first energy level to a second energy level;

a wide-field imaging system, in optical communication with the nanodiamond, to image the fluorescence emitted by the nitrogen vacancy to a point in an image plane; and

a detector array, disposed within the image plane, to sense the fluorescence emitted by the nitrogen vacancy.

18. The system of claim 17, wherein the laser is configured to illuminate the nanodiamond with another optical pulse within a relaxation time of the second energy level.

19. The system of claim 17, wherein the wide-field imaging system is configured to image fluorescence emitted by another nitrogen vacancy to the image plane.

20. The system of claim 17, further comprising:

a microwave source, in electromagnetic communication with the nanodiamond, to apply at least microwave pulse to the nitrogen vacancy so as to manipulate an electron spin state of the first nitrogen vacancy.